Advanced commissioning
6.18 Motor control
SINAMICS G115D distributed drive
268
Operating Instructions, 12/2020, FW V4.7 SP13, A5E48681219B-002
6.18.2.5
Moment of inertia estimator
Background
From the load moment of inertia and the speed setpoint change, the converter calculates the
accelerating torque required for the motor. Via the speed controller precontrol, the
accelerating torque specifies the main percentage of the torque setpoint. The speed
controller corrects inaccuracies in the precontrol (feed-forward control).
The more precise the value of the moment of inertia in the converter, the lower the
overshoot after speed changes.
Function
From the actual speed, the actual motor torque and the frictional torque of the load, the
converter calculates the total moment of inertia of the load and motor.
When using the moment of inertia estimator, we recommend that you also activate the
friction characteristic.
Friction characteristic (Page 266)
